Soil surface sealing is a major cause of decreased infiltration rates and increased surface runoff and erosion during a rainstorm. The objective of this paper is to quantify the effect of surface sealing on infiltrati...
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Soil surface sealing is a major cause of decreased infiltration rates and increased surface runoff and erosion during a rainstorm. The objective of this paper is to quantify the effect of surface sealing on infiltration for 3 layered soils with different textures for the upper layer and investigate the capability of best procedure to catch the formation of the seal and related consequences on water infiltration. Rainfall experiments were carried out to induce the formation of the seal. Meanwhile, Beerkan infiltration runs were carried out pouring water at different distances from the soil surface (best-H versus best-L runs, with a High and Low water pouring heights, respectively) for the same type of layered soils. Then, we determined saturated soil hydraulic conductivity, K-s, values from rainfall simulation and Beerkan infiltration experiments. Rainfall simulations carried out on soil layers having different depths allowed to demonstrate that infiltration processes were mainly driven by the seal and that K-s estimates were representative of the seal. Mean K-s values, estimated for the late-phase, ranged from 13.9 to 26.2 mm h(-1). Soil sealing induced an increase in soil bulk density by 38.7 to 42.1%, depending on the type of soil. Rainfall-deduced K-s data were used as target values and compared with those estimated by the Beerkan runs. best-H runs proved more appropriate than best-L runs, those last triggering no seal formation. The predictive potential of the three best algorithms (best-slope, best-intercept and best-steady) to yield a proper K-s estimate for the seal was also investigated. best-slope yielded negative K-s values in 87% of the cases for best-H runs. Positive values were obtained in 100% of the cases with best-steady and best-intercept. However, poorer fits were obtained with the latter algorithm. The comparison of K-s estimates with rainfall-deduced estimates allowed to identify best-steady algorithm with best-H run as the best combination. The
The recent breakthrough paper by Calude et al. has given the first algorithm for solving parity games in quasi-polynomial time, where previously the best algorithms were mildly subexponential. We devise an alternative...
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ISBN:
(纸本)9781509030187
The recent breakthrough paper by Calude et al. has given the first algorithm for solving parity games in quasi-polynomial time, where previously the best algorithms were mildly subexponential. We devise an alternative quasi-polynomial time algorithm based on progress measures, which allows us to reduce the space required from quasi-polynomial to nearly linear. Our key technical tools are a novel concept of ordered tree coding, and a succinct tree coding result that we prove using bounded adaptive multi-counters, both of which are interesting in their own right.
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